Summary
The King County Executive and King County Council will invest $7.8 million toward advancing projects to support clean water across the region through the longstanding WaterWorks grant program. WaterWorks grants, managed by King County’s Wastewater Treatment Division, protect and improve water quality through a wide variety of approaches including green stormwater infrastructure, restoration, research, community engagement, and education.
Summary
King County Executive Girmay Zahilay and the King County Council approved $7.8 million in WaterWorks grant funding for 99 projects that will improve water quality, prevent pollution, capture stormwater, and involve the community.
A few highlights include paid opportunities for youth to be involved in restoration along the Duwamish River, creating pocket forest parks along South Lake Union, and reducing harmful algal blooms.
“Supporting efforts we know are making a real impact in neighborhoods is essential to our work to improve water quality,” said Executive Zahilay. “This $7.8 million investment in cities and community-led projects will restore, protect, and enhance our local waterways, while supporting public health and ensuring future generations can enjoy the benefits of environmental stewardship.”
The program is administered by King County’s Wastewater Treatment Division, which protects local waterways by collecting and cleaning millions of gallons of wastewater each day. The WaterWorks grant program is funded through the division’s operating budget to support its core mission of protecting public health and the environment by investing in additional ways to support rivers, lakes, streams, and Puget Sound. Over the past 10 years, grantees have:
- Planted more than 24,000 trees and 124,000 other plants
- Installed 70 rain gardens and 189 cisterns or rain barrels
- Connected more than 174,000 community members with environmental stewardship programs, including more than 84,000 students
- Involved volunteers who donated more than 124,000 hours of their time
Last year alone, community organizations achieved big results for:
- Stormwater, installing six rain gardens and 30 cisterns or rain barrels
- Restoration, planting nearly 800 trees and 4,700 other plants
- Engagement, with volunteers donating 18,000 hours of their time
More than 23,000 community members connected with WaterWorks projects in 2025, including 13,000 students.
Past and current grantee, the Delridge Neighborhoods Development Association, shows the effects of WaterWorks grants in action. The association is a local nonprofit serving the diverse Delridge community in southwest Seattle through ecological restoration, affordable housing, and art and nature programs. Their WaterWorks projects have united community members to protect local waterways and salmon while reducing flooding in neighborhoods.
One major project has been restoring Delridge Wetland Park, a half-acre public park with wetlands that drain to Longfellow Creek. Longfellow Creek is one of the few remaining salmon-spawning streams in Seattle, but salmon populations in the creek struggle to spawn successfully each year — in part because stormwater runoff carries pollutants into the creek and degrades water quality.
With support from WaterWorks funding, Delridge Neighborhoods Development Association completed construction of a 360-foot-long bioswale system in 2023. The system slows and treats stormwater from nearly 15 acres of surrounding hills and neighborhoods before it reaches Longfellow Creek. By providing a channel that allows water to filter and soak into the ground, the bioswale recharges groundwater and reduces the total volume of polluted water that enters Longfellow Creek.
“By engaging neighbors and young people in hands-on environmental restoration, we’re building deeper connections to local ecosystems and the ability to take care of them,” said Ben Antonius, Restoration Program Manager for Delridge Neighborhoods Development Association. “Our volunteers are helping improve the forests around Longfellow Creek and creating a long-lasting culture of stewardship.”
With a newly awarded grant, the association will continue investing in restoration at Delridge Wetland Park, while hosting restoration volunteer events at 10 sites in the greater Longfellow Creek watershed and offering youth education and internship opportunities.
Of the 99 projects selected, 41 were selected through a competitive process managed by King County’s executive branch, totaling nearly $4.4 million in investments through 2027. Another 58 were selected through a King County Council process, totaling nearly $3.5 million.
The Wastewater Treatment Division works to ensure every dollar is spent in a way that leads to meaningful success for communities. Program staff work closely with grant recipients to support them with challenges during project implementation, monitor how funds are used, and track outcomes from each project. Amplifying the impact of King County funding, grant recipients contribute a portion of matching funds to the projects, as well as extensive volunteer time.
Examples of community-led water quality projects
Restoring 24-acre property in Renton into resilient ecological park
The City of Renton will restore a former agricultural property next to Springbrook Creek Headwaters, transforming it into a vibrant public park. In addition to invasive plant species removal and restoration, WaterWorks funding will be used to remove an aging, concrete-lined stormwater pond that provides limited water quality treatment. In its place, the city will build a natural wetland system that filters pollutants, increases groundwater infiltration, and supports rich native plant and animal communities.
Reducing harmful algal blooms in Woodinville’s Cottage lake
Friends of Cottage Lake will continue efforts to sequester phosphorus in Woodinville’s Cottage Lake. Phosphorus has been linked to toxic blue-green algal blooms that for decades have occurred in Cottage Lake and impacted downstream waters in Bear Creek and the Sammamish River. The phosphorus sequestration efforts began in 2024, and there have been meaningful improvements to the size, severity, and timing of the toxic blooms since the efforts began. An all-volunteer organization, Friends of Cottage Lake partners with the King County Lake Stewardship Program for volunteer training and water quality testing.
Engaging community to help restore native Lake Washington salmon population
The Three Rivers Chapter of Trout Unlimited will work on recovery for native freshwater kokanee salmon, a once-abundant and now vulnerable population. A key part of the project involves community members to monitor and reestablish native kokanee in three important streams in Lake Forest Park connected to Lake Washington. The engaging, hands-on salmon recovery activities will educate and inspire community interest, ultimately fostering greater long-term stewardship and advocacy for water quality improvements.
Creating pocket forest parks in South Lake Union
United Indians of All Tribes, as part of an ongoing partnership with Seattle Parks and Recreation, will use the Miyawaki method to plant a series of small native forest ecosystems along the shore of South Lake Union in Seattle. In a Miyawaki forest, trees are planted very close together, which mimics what occurs in a natural forest when a clearing in the canopy opens. The dense planting leads to rapid tree growth and increases in biodiversity. The project, part of an ongoing project with Seattle Parks and Recreation, will help water quality in Lake Union by expanding urban canopy coverage and filtering runoff.
Youth-led riparian and shoreline restoration along the Duwamish River
The Duwamish River Community Coalition will partner with PropagationNation and local partners to restore riparian habitat along a three-quarter mile stretch of the Duwamish River in South Park and Georgetown. The project will provide job training and paid employment opportunities to participants in the Duwamish Valley Youth Corps, who will lead invasive removal, site preparation, and installation of about 5,000 native trees and shrubs across the currently unvegetated shoreline.
The restoration will stabilize eroding shorelines, support infiltration of pollutants that would otherwise enter the Duwamish River, and eventually create shade that will cool water temperatures, supporting salmon and other cold-water species. The project will also engage community members through volunteer planting and stewardship events.
Previous grant recipients have conducted research into developing floating wetlands that help protect water quality at Shilshole Bay Marina, helped create a community garden that grows culturally relevant food in Shoreline, and partnered with students from the University of Washington to provide much-needed habitat in the lower Duwamish River.
Community partners that receive WaterWorks grant funding contribute to the King County Wastewater Treatment Division’s mission to protect the region’s water quality.
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Akiko Oda, Wastewater Treatment Division, 206-263-4190
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